Yes - expect the real-world range of an EV to drop as much as 20% in cold conditions. That's partly because the batteries don't perform as well in cold conditions (you may have noticed your smartphone's battery doesn't last as long in extremely cold weather), but also because you'll need more power-hungry features in winter (things like the heater and headlights).

There are steps you can take to extend the range when the weather's cold - for example, you can use the car's pre-conditioning feature to warm the car's cabin and defrost the windows while it's charging at home. This also has the advantage that the car's nice and toasty when you get in it in the morning!